Biology - Breathing and Exchange of Gases Question with Solution | TestHub
Identify the correct statements about human lungs.
(A). Each lung is enclosed in a double plural membrane with a fluid filled cavity between them.
(B). The left lung is larger and divided into three lobes and the right lung is smaller and divided into two lobes.
(C). Each lung has a number of air sacs, each with 10-12 alveoli.
(D). There are about 700 million alveoli in the lungs.
Choose thecorrectanswer from the options given below:
Options:
Answer:
Solution:
Statement (A) is correct. Each lung is enclosed in a double pleural membrane, and the narrow space between the two membranes is filled with pleural fluid, which reduces friction on the lung surface.
Statement (B) is incorrect. The right lung is larger and is divided into three lobes (superior, middle, and inferior), whereas the left lung is smaller (to accommodate the heart via the cardiac notch) and is divided into two lobes (superior and inferior).
Statement (C) is correct. The terminal bronchioles branch into respiratory bronchioles, which lead into alveolar ducts and then into alveolar sacs (air sacs). Each alveolar sac contains a cluster of alveoli.
Statement (D) is correct. The two lungs together contain approximately 300 to 700 million alveoli, which provide a massive surface area for gas exchange.
Therefore, the correct statements are (A), (C), and (D).
Answer: (A), (C) and (D) only.
